Gem-dihydropolyfluoroalkanes and monohydropolyfluoroalkenes, processes for their production, and use of gem-dihydropolyfluoroalkanes in cleaning compositions

ABSTRACT

A catalyic process is disclosed for producing fluorine-substituted hydrocarbon products of the formulae RCH 2 CF 2 R and RFC═CHR at an elevated temperature, from compounds of the formula RCHFCHFR, where each R is independently selected from the group consisting of —CF 3 , —CF 2 CF 3  and —CF 2 CF 2 CF 3  or where both R groups of a formula together are —(CF 2 ) 2 —, —(CF 2 ) 3 — or —(CF 2 ) 4 —. Suitable catalysts include carbon catalysts and catalysts containing at least one compound of a selected metal (e.g., Na, K, Rb, Cs, Y, La, Ce, Pr, Nd, Sm, Cr, Fe, Co, Rh, Ni, Cu, and/or Zn) supported on carbon. 
     The saturated gem-dihydro- products may also be produced by hydrofluorinating the corresponding olefinic product over such catalysts at an elevated temperature, and can be combined with various other miscible solvents to form compositions useful for cleaning. Compounds such as CF 3 CF 2 CH 2 CF 2 CF 3 , CF 3 CF 2 CH 2 (CF 2 ) 2 CF 3 , CF 3 CH═CF (CF 2 ) 2 CF 3 , CF 3 CF═CH(CF 2 ) 2 CF 3 , CF 3 CF 2 CH 2 (CF 2 ) 3 CF 3 , CF 3 (CF 2 ) 2 CH 2 (CF 2 ) 2 CF 3 , CF 3 CH═CF(CF 2 ) 3 CF 3 , CF 3 CF═CH (CF 2 ) 3 CF 3 , CF 3 (CF 2 ) 2 CH 2 (CF 2 ) 3 CF 3 , CF 3 CF 2 CH 2 (CF 2 ) 4 CF 3 , CF 3 CH═CF(CF 2 ) 4 CF 3 , CF 3 CF═CH (CF 2 ) 4 CF 3 , CF 3 CF 2 CH═CF(CF 2 ) 3 CF 3 , CF 3 CF 2 CF═CH(CF 2 ) 3 CF 3  and                    
     and azeotropic compositions such as azeotropes of CF 3 CH 2 CF 2 CF 2 CF 3  and/or CF 3 CF 2 CH 2 CF 2 CF 3  with methanol, ethanol, or isopropanol are disclosed.

This is a division of application Ser. No. 07/751,019, filed Aug. 28,1991, now U.S. Pat. No. 5,268,122.

FIELD OF THE INVENTION

This invention relates to fluorine-substituted hydrocarbon compounds,their production, and their use for cleaning solid surfaces, and moreparticularly to polyfluorooctanes, polyfluorooctenes,polyfluoroheptanes, polyfluoroheptenes, and linear and cyclicpolyfluorohexanes, polyfluorohexenes, polyfluoropentanes,polyfluoropentenes, polyfluorobutanes, and polyfluorobutenes, theirproduction from linear and cyclic polyfluoroalkane or polyfluoroolefinstarting materials, and the use of linear and cyclic polyfluoroalkanesas solvents.

BACKGROUND OF THE INVENTION

Various organic solvents have been used as cleaning liquids for theremoval of contaminants from contaminated articles and materials.Certain fluorine-containing organic compounds such as1,1,2-trichloro-1,2,2-trifluoroethane have been reported as useful forthis purpose, particularly with regard to cleaning organic polymers andplastics which may be sensitive to other more common and more powerfulsolvents such as trichloroethylene or perchloroethylene. Recently,however, there have been efforts to reduce the use of certain compoundssuch as trichlorotrifluoroethane which also contain chlorine because ofa concern over their potential to deplete ozone, and to thereby affectthe layer of ozone that is considered important in protecting theearth's surface from ultraviolet radiation.

Boiling point, flammability and solvent power can often be adjusted bypreparing mixtures of solvents. For example, certain mixtures of 1,1,2,-trichloro-1,2,2-trifluoroethane with other solvents (e.g., isopropanoland nitromethane) have been reported as useful in removing contaminantswhich are not removed by 1,1,2-trichloro-1,2,2-trichloroethane alone,and in cleaning articles such as electronic circuit boards where therequirements for a cleaning solvent are relatively stringent, i.e., itis generally desirable in circuit board cleaning to use solvents whichhave low boiling points, are non-flammable, have low toxicity, and havehigh solvent power so that flux such as rosin and flux residues whichresult from soldering electronic components to the circuit board can beremoved without damage to the circuit board substrate).

While boiling point, flammability, and solvent power can often beadjusted by preparing mixtures of solvents, the utility of the resultingmixtures can be limited for certain applications because the mixturesfractionate to an undesirable degree during use. Mixtures can alsofractionate during recovery, making it more difficult to recover asolvent mixture with the original composition. Azeotropic compositions,with their constant boiling and constant composition characteristics,are thus considered particularly useful.

Azeotropic compositions exhibit either a maximum or minimum boilingpoint and do not fractionate upon boiling. These characteristics arealso important in the use of the solvent compositions in certaincleaning operations, such as removing solder fluxes and flux residuesfrom printed circuit boards. Preferential evaporation of the morevolatile components of the solvent mixtures, which would be the case ifthe mixtures were not azeotropes, or azeotrope-like, would result inmixtures with changed compositions which may have less desirableproperties (e.g., lower solvency for contaminants such as rosin fluxesand/or less inertness toward the substrates such as electricalcomponents).

Azeotropic characteristics are also desirable in vapor degreasingoperations where redistilled material is usually used for finalrinse-cleaning. Thus, the vapor defluxing or degreasing system acts as astill. Unless the solvent composition exhibits a constant boiling point(i.e., is an azeotrope or is azeotrope-like) fractionation will occurand undesirable solvent distribution may act to upset the safety andeffectiveness of the cleaning operation.

A number of azeotropic compositions based upon halohydrocarbonscontaining fluorine have been discovered and in some cases used assolvents for the removal of solder fluxes and flux residues from printedcircuit boards and for miscellaneous vapor degreasing applications. Forexample, U.S. Pat. No. 2,999,815 discloses the azeotrope of1,1,2-trichloro-1,2,2-trifluoroethane with acetone; U.S. Pat. No.3,903,009 discloses a ternary azeotrope of1,1,2-trichloro-1,2,2-triflouroethane with nitromethane and ethanol;U.S. Pat. No. 3,573,213 discloses an azeotrope of1,1,2-trichloro-1,2,2-trifluoroethane with nitromethane; U.S. Pat. No.3,789,006 discloses the ternary azeotrope of1,1,2-trichloro-1,2,2-trifluoroethane with nitromethane and isopropanol;U.S. Pat. No. 3,728,268 discloses the ternary azeotrope of1,1,2-trichloro-1,2,2-trifluoroethane with acetone and ethanol; U.S.Pat. No. 2,999,817 discloses the binary azeotrope of1,1,2-trichloro-1,2,2-trifluoroethane and methylene chloride (i.e.,dichloromethane); and U.S. Pat. No. 4,715,900 discloses ternarycompositions of trichlorotrifluoroethane, dichlorodifluoroethane, andethanol or methanol.

As noted above, many solvent compositions which have proven useful forcleaning contain at least one component which is a halogen-substitutedhydrocarbon containing chlorine, and there have been concerns raisedover the ozone depletion potential of halogen-substituted hydrocarbonswhich contain chlorine. Efforts are being made to develop compositionswhich may at least partially replace the chlorine containing componentswith other components having lower potential for ozone depletion.Azeotropic compositions of this type are of particular interest.

Means of synthesizing various fluorine-substituted alkanes have beenreported.

U.S. Pat. No. 2,917,559 discloses a vapor phase process for theproduction of 2-fluoropropane by the reaction of HF and propylene overan activated carbon catalyst.

U.S. Pat. No. 2,975,220 discloses compounds of the general formulaR(CH₂CF₂)nQ, where n is an integer and Q is halogen or hydrogen and R isa halogenated radical. These compounds (e.g., CF₃CH₂CF₂CF₂CF₃) may beprepared by reacting vinylidene fluoride with certain telogens.

U.S. Pat. No. 3,520,786 discloses a process for the preparation ofcycloalkanes by electrolyzing a solution of halocarbons having 3-6 ringcarbons of the general composition C(R₁)RR—C(₁₋₄)RR—C(R₂)RR, where R maybe an alkyl group, hydrogen, or a halogen; R₁ is halogen; and R₂ may bea halogen, quarternary ammonium salt or a tosylate; and isolating thecorresponding cycloalkane.

U.S. Pat. No. 4,902,838 discloses a process for the isomerization of C₂to C₆ hydrofluorocarbons having lesser thermodynamic stability tohydrofluorocarbons having greater thermodynamic stability byisomerization in the vapor phase of at least one C₂ to C₆ saturatedhydrofluorocarbon with a catalyst comprising aluminum fluoride. Theisomerization of 1,1,2,2-tetrafluoroethane, a vicinal-dihydrofluorocarbon, to 1,1,1,2-tetrafluoroethane, a geminal-dihydrofluorocarbon, is exemplified.

Eur. Pat. Appln. No. 365,296 discloses a process for the preparation of1,1,1,2-tetrafluoroethane by the isomerization of1,1,2,2-tetrafluoroethane over a fluorination catalyst. The onlycatalyst examplified is chromia.

C. Zhanxun et al., Proc. Annu. Int. Conf. Plasma Chem. Technol., 4th,Meeting Date 1987, 173-9 (1989) and C. Zhanxun et al., Adv. Low-Temp.Plasma Chem., Technol., Appl., 2, 265-73 (1988) discloses the formulaCF₃CF₂CH₂CF₂CF₃ as a theoretical product from the degradation ofplasma-polymerized tetrafluoroethylene.

There are also means of synthesizing various fluorine-substitutedalkenes. For example, U.S. Pat. Nos. 4,820,883 and 4,820,884 disclosethe use of activated carbon for the preparation of unsaturatedfluorocarbons by defluorinating perfluoro compounds.

SUMMARY OF THE INVENTION

In accordance with this invention, novel saturated compounds areprovided which contain no chlorine and which may be used alone or incombination with various other miscible solvents as agents for cleaningsolid surfaces. Novel unsaturated compounds, which may be used forpreparation of the corresponding saturated compounds, are also providedin accordance with this invention.

The novel compounds of this invention include the group ofdihydropolyfluoropentanes, dihydropolyfluorohexanes,dihydropolyfluoroheptanes and dihydropolyfluorooctanes represented bythe formula R¹CH₂CF₂R² wherein R¹ is selected from the group consistingof —CF₂CF₃ and —CF₂CF₂CF₃ and R² is selected from the group consistingof —CF₃, —CF₂CF₃ and —CF₂CF₂CF₃ or wherein R¹ and R² together are—CF₂)₃—; and the group of monohydropolyfluoroolefins represented by theformula R³X¹C═CX²R⁴ wherein R³ is selected from the group consisting of—CF₃ and —CF₂CF₃, R⁴ is selected from the group consisting of—CF₂CF₂CF₃, —CF₂CF₂CF₂CF₃ and —CF₂CF₂CF₂CF₂CF₃, and X¹ and X² aredifferent and are selected from the group consisting of hydrogen andfluorine, provided that when R³ is —CF₂CF₃ R⁴ is —CF₂CF₂CF₂CF₃.

A process is provided in accordance with this invention for preparingcompounds selected from the group consisting ofgem-dihydropolyfluoroalkanes of the formulae R⁵CH₂R⁶ and R⁵CF₂CH₂R⁶ andmonohydropolyfluoroolefins of the formulae R⁵CH═CFR⁶ and R⁵CF═CHR⁶wherein R⁵ and R⁶ are each independently selected from the groupconsisting of —CF₃, —CF₂CF₃ and —CF₂CF₂CF₃, or wherein R⁵ and R⁶together are —CF₂)₂—, —(CF₂)₃— or —CF₂)₄—, which comprises the step ofcontacting a saturated starting material of the formula R⁵CHFCHFR⁶wherein R⁵ and R⁶ are as above, at an elevated temperature with a carboncatalyst or a catalyst containing at least one compound of a metalselected from the group consisting of sodium, potassium, rubidium,cesium, yttrium, lanthanum, cerium praseodymium, neodymium, samarium,chromium, iron, cobalt, rhodium, nickel, copper, zinc, and mixturesthereof, supported on carbon.

Another process is provided in accordance with this invention forpreparing gem-dihydropolyfluoroalkanes of the formula R⁷CH₂CF₂R⁸ whereinR⁷ and R⁸ are each independently selected from the group consisting of—CF₃, —CF₂CF₃ and —CF₂CF₂CF₃ or wherein R⁷ and R⁸ together are —(CF₂)₂—,—(CF₂)₃ or —(CF₂)₄—, which comprises the step of reacting an olefinicstarting material of the formula R⁷CH═CFR⁸ wherein R⁷ and R⁸ are asabove, with HF at an elevated temperature in the presence of a carboncatalyst or a catalyst of at least one compound of a metal selected fromthe group consisting of sodium, potassium, rubidium, cesium, yttrium,lanthanum, cerium praseodymium, neodymium, samarium, chromium, iron,cobalt, rhodium, nickel, copper, zinc, and mixtures thereof, supportedon carbon. The gem-dihydropolyfluoroalkanes may be used in combinationwith other miscible solvents (e.g., alcohols, ethers, esters, ketones,nitrogen-containing organic compounds such as acetonitrile andnitromethane, and halogenated hydrocarbons) as agents for cleaning solidsurfaces.

DETAILED DESCRIPTION OF THE INVENTION

This invention provides novel saturated linear polyfluorohydrocarbonswhich contain two hydrogen atoms per molecule which are attached to thesame carbon atom (i.e., gem-dihydropolyfluoroalkanes). The novelgem-dihydropolyfluoroalkanes of this invention have the formulaR¹CH₂CF₂R² wherein R¹ is selected from the group consisting of —CF₂CF₃and —CF₂CF₂CF₃ and R² is selected from the group consisting of —CF₃,—CF₂CF₃ and —CF₂CF₂CF₃ or wherein R¹ and R² together are —CF₂)₃—, andinclude the dihydropolyfluorooctanes CF₃CF₂CH₂CF₂CF₂CF₂CF₂CF₃ andCF₃CF₂CF₂CH₂CF₂CF₂CF₂CF₃; the dihydropolyfluoroheptanesCF₃CF₂CH₂CF₂CF₂CF₂CF₃ and CF₃CF₂CF₂CH₂CF₂CF₂CF₃; thedihydropolyfluorohexane CF₃CF₂CH₂CF₂CF₂CF₃; the dihydropolyfluoropentaneCF₃CF₂CH₂CF₂CF₃; and the compound

This invention also provides novel polyfluoroolefins which contain onehydrogen atom per molecule which is attached to one of the carbonsforming the olefinic bond. The novel monohydropolyfluoroolefines of thisinvention have the formula R³X¹C═CX²R⁴ wherein R³ is selected from thegroup consisting of —CF₃ and —CF₂CF₃, R⁴ is selected from the groupconsisting of —CF₂CF₂CF₃, —CF₂CF₂CF₂CF₃ and —CF₂CF₂CF₂CF₂CF₃, and X¹ andX² are different and are selected from the group consisting of hydrogenand fluorine, provided that when R³ is —CF₂CF₃ R⁴ is —CF₂CF₂CF₂CF₃, andinclude the monohydropolyfluorohexenes CF₃CH═CFCF₂CF₂CF₃ andCF₃CF═CHCF₂CF₂CF₃; the monohydropolyfluoroheptanes CF₃CH═CFCF₂CF₂CF₂CF₃and CF₃CF═CHCF₂CF₂CF₂CF₃; and the monohydropolyfluorooctenesCF₃CH═CFCF₂CF₂CF₂CF₃, CF₃CF═CHCF₂CF₂CF₂CF₂CF₃, CF₃CF₂CH═CFCF₂CF₂CF₂CF₃and CF₃CF₂CF═CHCF₂CF₂CF₂CF₃.

A process provided in accordance with this invention for preparingcompounds selected from the group consisting ofgem-dihydropolyfluoroalkanes of the formula R⁵CH₂CF₂R⁶ and R⁵CF₂CH₂R⁶and monohydropolyfluorolefins of the formulae R⁵CH═CFR⁶ and R⁵CF═CHR⁶wherein R⁵ and R⁶ are each selected from the group consisting of —CF₃,—CF₂CF₃ and —CF₂CF₂CF₃ or wherein R⁵ and R⁶ together are —CF₂)₂—,—CF₂)₃— or —(CF₂)₄—, comprises the step of contacting a saturatedstarting material of the formula R⁵CHFCHFR⁶, wherein R⁵ and R⁶ are asabove, at an elevated temperature with a carbon catalyst or a catalystof at least one compound of a metal selected from the group consistingof sodium, potassium, rubidium, cesium, yttrium, lantanum, ceriumpraseodymium, neodymium, samarium, chromium, iron, cobalt, rhodium,nickel, copper, zinc, and mixtures thereof, supported on carbon. Thecarbon which is used as a catalyst can be either unwashed or acidwashed. The washed carbon is normally prepared by treating the carbonwith acid containing neither phosphorus nor sulfur, to removeimpurities. Preferably a subsequent treatment is done with hydrofluoricacid to further reduce impurities, especially silicon. After suchtreatment the ashed carbon typically contains less than about 0.1% ash.Commercially available carbons useful in the process of this inventioninclude those sold under the following trademarks: Darco™, Nuchar™,Columbia SBV™, MBV™, Columbia MBQ™, Columbia JXC™, Columbia CXC™, CalgonPCB™, and Barnaby Cheny NB™. The carbon catalyst can be in the form ofpowder, granules, or pellets, etc. High surface area carbons such asCalgon® PCB and Carbosieve G® are preferred over low surface areacarbons. Examples of acids which may be used in the first acid wash ofthis process include organic acids such as acetic acid and inorganicacids, e.g., HCl or HNO₃. Preferably hydrochloric acid or nitric acid isused. The acid treatment may be accomplished in several ways. Apreferred embodiment is described below.

A carbon catalyst is soaked overnight with gentle stirring in a 1Msolution of the acid prepared in deionized water. The carbon catalyst isseparated and washed with deionized water until the pH of the washingsis about 3. The carbon catalyst is then soaked again, with gentlestirring in a 1M solution of the acid prepared in deionized water, forabout 12 to 24 hours. The carbon catalyst is then finally washed withdeionized water until the washings are substantially free of the anionof the acid (e.g., cl⁻ or NO₃ ⁻), when tested by standard procedures.The carbon catalyst is then separated and dried at about 120°C. a sampleof this washed carbon is the soaked, if desired, in 1 M HF prepared indeionized water for about 48 hours at room temperature with occasionalstirring in an HF-resistant container. The carbon catalyst is separatedand washed repeatedly with deionized water until the pH of the washingsis greater than 4. The carbon catalyst is then dried at about 150° C.,followed by calcination at about 300° C. Suitable carbons include acidwashed carbons (e.g., carbons essentially free of K⁻) or unwashedcarbons (e.g., carbons containing from about 0.1 to about 2 percent byweight K⁻). Metal compounds supported on carbon may also be used foreither the rearrangement of vicinal-dehydropolyfluoroalkanes togeminal-dihydropolyfluoroalkanes or the dehydro-fluorination ofvicinal-dihydropolyfluoroalkanes to mixtures ofmonohydropolyfluoroolefins. The metals of the compounds may be selectedfrom the group consisting of sodium, potassium, rubidium, cesium,yttrium, the lanthanide series especially, lanthanum, cerium,praseodymium, neodymium, and samarium, chromium, iron, cobalt, rhodium,nickel, copper, zinc, and mixtures thereof. Example compounds includethe acetates, nitrates, chlorides and/or fluorides of said metals. Thecarbon supported metal compounds may be prepared from soluble metalsalts by known art procedures. Generally, where carbon-supported metalcompounds are used, the metals comprise from about 0.5 to 30 percent byweight of the catalyst.

HF may be added during the isomerization. Through catalyst selection andprocess control, as described herein, the ratio ofmonohydropolyfluoro-olefins to geminal-dihydropolyfluoroalkanes can beadjusted. For example, higher pressures favor the formation ofgeminal-dihydropolyfluoroalkanes. Alternatively, the proportion ofmonohydropolyfluoroolefins may be increased by adding inert gases suchas nitrogen, helium or argon to the reactor feed.

Unreacted starting materials and intermediates, if any, may be separatedfrom the reaction products by conventional means (e.g., distillation)and recycled back into the reactor.

The saturated starting material used for this process has the samenumber of carbon atoms as the desired gem-dihydropolyfluoroalkane and/ormonohydropolyfluoroolefin. Thus, the gem-dihydropolyfluoroalkaneCF₃CH₂CF₂CF₃ can be produced by isomerizing CF₃CFHCFHCF₃ over acarbon-containing catalyst in accordance with this invention; agem-dihydropolyfluoroalkane selected from the group consisting ofCF₃CH₂CF₂CF₂CF₃ and CF₃CF₂CH₂CF₂CF₃ can be produced by isomerizingCF₃CHFCHFCF₂CF₃ over a carbon-containing catalyst in accordance withthis invention; a gem-dihydropolyfluoroalkane selected from the groupconsisting of CF₃CH₂CF₂CF₂CF₂CF₃ and CF₃ CF₂CH₂CF₂CF₂CF₃ can be producedby isomerizing a CF₃CHFCHFCF₂CF₂CF₃ over a carbon-containing catalyst inaccordance with this invention; the gem-dihydropolyfluoroalkane CF₃CF₂CH₂CF₂CF₂CF₃ can be produced by isomerizing CF₃CF₂CHFCHFCF₂CF₃ over acarbon-containing catalyst in accordance with this invention; agem-dihydropoly-fluoroalkane selected from the group consisting ofCF₃CF₂CH₂CF₂CF₂CF₂CF₃ and CF₃CF₂CHFCHFCF₂CF₂CF₃ over a produced byisomerizing CF₃CF₂CHFCHFCF₂CF₂CF₃ over a carbon-containing catalyst inaccordance with this invention; a gem-dihydropolyfluoroalkane selectedfrom the group consisting of CF₃CH₂CF₂CF₂CF₂CF₂ CF₃ and CF₃CF₂CH₂CF₂CF₂CF₂CF₃ can be produced by isomerizing CF₃CHFCHFCF₂CF₂CF₂CF₃over a carbon-containing catalyst in accordance with this invention; thegem-dihydropolyfluoroalkane CF₃CF₂CF₂CH₂CF₂CF₂CF₂CF₃ can be produced byisomerizing CF₃CF₂CF₂CHFCHFCF₂CF₂CF₃ over a carbon-containing catalystin accordance with this invention; a gem-dihydropolyfluoroalkaneselected from the group consisting of CF₃CH₂CF₂CF₂CF₂CF₂CF₂CF₃ andCF₃CF₂CH₂CF₂CF₂CF₂CF₂CF₃ can be produced by isomerizingCF₃CHFCHFCF₂CF₂CF₂CF₂CF₃ over a carbon-containing catalyst in accordancewith this invention; a gem-dihydropolyfluoroalkane selected from thegroup consisting of CF₃CF₂CH₂CF₂CF₂CF₂CF₂CF₃ andCF₃CF₂CF₂CH₂CF₂CF₂CF₂CF₃ can be produced by isomerizingCF₃CF₂CHFCHFCF₂CF₂CF₂CF₃ over a carbon-containing catalyst in accordancewith this invention; the compound

can be produced by isomerizing

over a carbon-containing catalyst in accordance with this invention; thecompound

can be produced by isomerizing

over a carbon-containing catalyst in accordance with this invention; andthe compound

can be produced by isomerizing

over a carbon-containing catalyst in accordance with this invention.

The monohydropolyfluoroolefin CF₃CH═CFCF₃ can be produced bydehydrofluorinating CF₃CFHCFHCF₃ over a carbon-containing catalyst inaccordance with this invention; a monohydropolyfluoroolefin selectedfrom the group consisting of CF₃CH═CFCF₂CF₃ and CF₃CF═CHCF₂CF₃ can beproduced by dehydrofluorinating CF₃CFHCFHCF₂CF₃ over a carbon-containingcatalyst in accordance with this invention; a monohydropolyfluoroolefinselected from the group consisting of CF₃CH═CFCF₂CF₂CF₃ andCF₃CF═CHCF₂CF₂CF₃ can be produced by dehydrofluorinatingCF₃CFHCFHCF₂CF₂CF₃ over a carbon-containing catalyst in accordance withthis invention; the monohydropolyfluoroolefin CF₃CF₂CH═CFCF₂CF₃ can beproduced by dehydrofluorinating CF₃CF₂CFHCFHCF₂CF₃ over acarbon-containing catalyst in accordance with this invention; amonohydropolyfluoroolefin selected from the group consisting ofCF₃CF₂CH═CFCF₂CF₂CF₃ and CF₃CF₂CF═CHCF₂CF₂CF₂CF₃ can be produced bydehydrofluorinating CF₃CHFCHFCF₂CF₂CF₂CF₃ over a carbon-containingcatalyst in accordance with this invention; a monohydropolyfluoroolefinselected from the group consisting of CF₃CH═CFCF₂CF₂CF₂CF₃ andCF₃CF═CHCF₂CF₂CF₂CF₃ can be produced by dehydro-fluorinatingCF₃CF₃CHFCHFCF₂CF₂CF₂CF₃ over a carbon-containing catalyst in accordancewith this invention; the monohydropolyfluoroolefinCH₃CF₂CF₂CH═CFCF₂CF₂CF₃ can be produced by dehydrofluorinatingCF₃CF₂CF₂CHFCHFCF₂CF₂CF₃ over a carbon-containing catalyst in accordancewith this invention; a monohydropolyfluoroolefin selected from the groupconsisting of CF₃CH═CFCF₂CF₂CF₂CF₂ CF₃ and CF₃CF═CHCF₂CF₂CF₂CF₂CF₃ canbe produced by dehydrofluorinating CF₃CHFCHFCF₂CF₂CF₂CF₂CF₃ over acarbon-containing catalyst in accordance with this invention; amonohydropolyfluoroolefin selected from the group consisting ofCF₃CF₂CH═CFCF₂CF₂CF₂CF₃ and CF₃CF₂CF═CHCF₂CF₂CF₂CF₃ can be produced bydehydrofluorinating CF₃CF₂CHFCHFCF₂CF₂CF₂CF₃ over a carbon-containingcatalyst in accordance with this invention; the compound

can be produced by dehydrofluorinating

over a carbon-containing catalyst in accordance with this invention; thecompound

can be produced by dehydrofluorinating

over a carbon-containing catalyst in accordance with this invention; andthe compound

can be produced by dehydrofluorinating

over a carbon-containing catalyst in accordance with this invention.

The isomerization and/or dehydrofluorinating can be carried out attemperatures in the range of from about 200° C. to about 500° C. Thepreferred temperature range is from about 300° C. to about 450° C. Thepressure of the reaction may be within a wide range, from less than 1atmosphere to extremely high pressures (e.g., 50 atmospheres or more),but normally pressures from 1 atmosphere to about 30 atmospheres arepreferred, with higher pressures (e.g., 5 atmospheres or more) favoringthe production of saturated products. The reaction time may also bewithin a wide range, depending upon such factors as the materialspresent, temperature and the conversion desired. Normally reaction timesbetween about 15 seconds and 10 hr are suitable. If the olefinicproducts are desired, reaction times of about 30 seconds at about 1atmosphere and temperatures within the range of about 250° C. to 350° C.are considered suitable in a continuous flow reactor. If the saturatedproducts are desired, reaction times of about 150 seconds at about 7atmospheres and temperatures within the range of about 250° C. to 350°C. are considered suitable in a continuous flow reactor.

Without limiting the invention to a particular theory of operation, itis believed that the saturated starting material may be sequentiallyconverted during reaction to an olefinic material containing onehydrogen by removal of HF, and then hydrofluorinated back to a saturatedend product wherein the hydrogen atoms are positioned on the samecarbon.

Various saturated starting materials for this process may be prepared byhydrogenating olefinic perfluoroolefins of the type produced in U.S.patent application Ser. No. 07/595,839. The hydrogenation may beconducted in accordance with the procedures disclosed in U.S. patentapplication Ser. No. 07/595,840. U.S. patent application Ser. No.07/595,839 and U.S. patent application Ser. No. 07/595,840 are herebyincorporated by reference in their entirety.

The vicinal linear dihydropolyfluoroalkane starting materials of thisinvention selected from the group consisting of CF₃CHFCHFCF₃,CF₃CF₂CHFCHFCF₂CF₃, CF₃CHFCHFCF₂CF₂CF₃, CF₃CF₂CHFCHFCF₂CF₃,CF₃CHFCHFCF₂CF₂CF₂CF₃, CF₃CF₂CHFCHFCF₂CF₂CF₃, CF₃CHFCHFCF₂CF₂CF₂CF₂CF₃,CF₃CF₂CHFCHFCF₂CF₂CF₂CF₃, and CF₃CF₂CF₂CHFCHFCF₂CF₂CF₃, may be preparedby a process which comprises reacting an appropriated olefinic startingmaterial in the vapor phase with hydrogen over a Group VIII metalcatalyst. Preferably the catalyst in a supported palladium. Theappropriate olefinic starting material has the same number of carbonatoms as the desired vicinal linear dihydropolyfluoroalkane and isselected from the group consisting of CF₃CF═CFCF₃, CF₃CF═CFCF₂CF₃,CF₃CF═CFCF₂CF₂CF₃, CF₃CF₂CF═CFCF₂CF₃, CF₃CF═CFCF₂CF₂CF₃,CF₃CF₂CF═CFCF₂CF₂CF₃, CF₃CF═CFCF₂CF₂CF₂CF₂CF₃, CF₃CF₂CF═CFCF₂CF₂CF₂CF₃,and CF₃CF₂CF₂CF═CFCF₂CF₂CF₃; and has its olefinic bond between thecarbon atoms which correspond to the hydrogen-bearing carbons in saiddihydropolyfluoroalkanes. Unsupported metal catalysts and supportedmetal catalysts wherein the metal is palladium, rhodium or ruthenium areparticularly suitable for use in this hydrogenation process. Supportssuch as carbon or alumina may be employed. Supported palladium catalystsare preferred.

The vapor phase reduction can be carried out in the range of from abut50° C. to about 250° C.; the preferred temperature range is from about100° C. to about 200° C. The pressure of the hydrogenation may varywidely from less than 1 atmosphere to 20 or more atmospheres. The molarratio of hydrogen to olefinic starting material for this process ispreferably between about 0.5:1 and 4:1, and is more preferably betweenabout 0.5:1 and 1.5:1.

The vicinal dihydropolyfluorocycloalkane starting materials of thisinvention selected from the group consisting of 1H,2H-perfluorocyclobutane, 1H,2H-perfluorocyclopentane, and1H,2H-perfluorocyclohexane may be prepared by a process which comprisesthe step of reacting an olefinic starting material which has the samenumber of carbons as said dihydropolyfluorocycloalkane and is selectedform the group consisting of perfluorocyclobutene,perfluorocyclopentene, and perfluorocyclohexane, at an elevatedtemperature with hydrogen in the presence of at least one materialselected from the group consisting of iodine and hydrogen iodide (HI),or with hydrogen iodide. Iodine and /or HI is used for thishydrogenation in accordance with the teachings of U.S. patentapplication Ser. No. 07/607,754. Hydrogen iodide for the reaction may beprovided by several methods. For example the reaction may be run withstoichiometric HI. Alternatively, the reaction may be run with catalyticamounts of HI in the presence of hydrogen. The reaction may also be runwith hydrogen using catalytic amounts of iodine. The latter method ispreferred for batch reactions and ease of handling. This reaction may beaccomplished in the absence of supported metal catalysts; and indeed thecatalyst for this reaction typically consists essentially of iodineand/or hydrogen iodide. The reaction temperature of this reaction shouldgenerally be from 100° C. to 500° C. A preferred temperature is from200° C. to 400° C. This reaction may be run at a pressure of from about50 psi to about 5000 psi, with 500 psi to 1500 psi being preferred.

The amount of hydrogen provided for contact with the olefinic startingmaterial (either by addition of HI or by feed of hydrogen gas) shouldrepresent at least one molecule of hydrogen for each olefinic bond andis preferably no more than 10 times said minimum (i.e., the molar rationof hydrogen available for reacting to olefinic starting material ispreferably between 10:1 and 1:1). When hydrogen gas is used, thehydrogen can be fed either in the pure state or diluted with an inertgas (e.g., nitrogen, helium or argon).

Another process provided in accordance with this invention for preparinggem-dihydropolyfluoroalkanes of the formula R⁷Ch₂CF₂R⁸ wherein R⁷ and R⁸are each selected from the group consisting of —CF₃, —CF₂CF₃ and—CF₂CF₂CF₃ or wherein R⁷ and R⁸ together are —(CF₂)_(n)— when n is aninteger from 2 to 4, which comprises the step or reacting an olefinicstarting material of the formula R⁷CH═CFR⁸ (Wherein R⁷ and R⁸ are asabove) with HF at an elevated temperature in the presence of a carboncatalyst or a catalyst of at least one compound of a metal selected formthe group consisting of sodium, potassium, rubidium, cesium, yttrium,lanthanum, cerium praseodymium, neodymium, samarium, chromium, iron,cobalt, rhodium, nickel, copper, zinc, and mixtures thereof, supportedon carbon.

The olefinic starting material used for this process has the same numberof carbon atoms as the desired gem-dihydropolyfluoroalkane. Thus, thegem-dihydropolyfluoroalkane CF₃CH₂CF₂CF₃ can be produced by reactingCF₃CH═CFCF₃ with HF over a carbon-containing catalyst in accordance withthis invention; the gem-dihydropolyfluoroalkane CF₃CH₂CF₂CF₂CF₃ can beproduced by reacting CF₃CH═CFCF₂CF₃ with HF over a carbon-containingcatalyst in accordance with this invention; thegem-dihydropolyfluoroalkane CF₃CF₂CH₂CF₂CF₃ can be produced by reactingCF₃CF₂CH═CFCF₃ with HF over a carbon-containing catalyst in accordancewith this invention; the gem-dihydropolyfluoroalkane CF₃CH₂CF₂CF₂CF₂CF₃can be produced by reacting CF₃CH═CFCF₂CF₂CF₃ with HF over acarbon-containing catalyst in accordance with this invention; thegem-dihydropolyfluoroalkane CF₃CF₂CH₂CF₂CF₂CF₃ can be produced byreacting CF₃CF₂CH═CFCF₂CF₃ and/or CF₃CF₂CF₂CH═CFCF₃ with HF over acarbon-containing catalyst in accordance with this invention; thegem-dihydropolyfluoroalkane CF₃CH₂CF₂CF₂CF₂CF₂CF₃ can be produced byreacting CF₃CH═CFCF₂CF₂CF₂CF₃ with HF over a carbon-containing catalystin accordance with this invention; the gem-dihydropolyfluoroalkaneCF₂CF₂CH₂CF₂CF₂CF₂CF₃ can be produced by reacting CF₂CF₂CH═CFCF₂CF₂CF₃and/or CF₃CF═CHCF₂CF₂CF₂CF₃ with HF over a carbon-containing catalyst inaccordance with this invention; the gem-dihydropolyfluoroalkaneCF₃CF₂CF₂CH₂CF₂CF₂ CF₃ can be produced by reacting CF₃CF₂CF₂CH═CFCF₂CF₃with HF over a carbon-containing catalyst in accordance with thisinvention; the gem-dihydropolyfluoroalkane CF₃CH₂CF₂CF₂CF₂CF₂CF₂CF₃ canbe produced by reacting CF₃CH═CFCF₂CF₂CF₂CF₂CF₃ with HF over acarbon-containing catalyst in accordance with this invention; thegem-dihydropolyfluoroalkane CF₃CF₂CH₂CF₂CF₂CF₂CF₂CF₃ can be produced byreacting CF₃CF═CHCF₂CF₂CF₂CF₂CF₃ and/or CF₃CF₂CH═CFCF₂CF₂CF₂CF₃ with HFover a carbon-containing catalyst in accordance with this invention; thegem-dihydropolyfluoroalkane CF₃CF₂CF₂CH₂CF₂CF₂CF₂CF₃ can be produced byreacting CF₃CF₂CF₂CH═CFCF₂CF₂CF₃ and/or CF₃CF₂CF═CHCF₂CF₂CF₂CF₃ with HFover a carbon-containing catalyst in accordance with this invention; thecompound

can be produced by reacting

with HF over a carbon-containing catalyst in accordance with thisinvention; the compound

can be produced by reacting

with HF over a carbon-containing catalyst in accordance with thisinvention; and the compound

can be provided by reacting

with HF over a carbon-containing catalyst in accordance with thisinvention.

The reaction temperature for this hydrofluorination reaction shouldgenerally be from 200° C. to 500° C. A preferred temperature range isfrom 300° C. to 450° C. The pressure of the reaction may be within awide range, from less than 1 atmosphere to extremely high pressures(e.g., 50 atmospheres or more), but normally pressures from 1 atmosphereto about 30 atmospheres are preferred, with higher pressures (e.g., 5atmospheres or more) favoring the production of saturated products. Thereaction time for the hydrofluorination may also be within a wide rangedepending upon such factors as the materials present and the yielddesired. Normally the reaction times between about 15 seconds and 10 hrare suitable.

The amount of hydrogen fluoride provided for contact with the olefinicstarting material should represent at least one molecule of hydrogenfluoride for each olefinic bond to be saturated, and is preferably 10times said minimum, or less (i.e., the molar ratio of hydrogen fluorideavailable for reacting to olefinic starting material is preferablybetween 10:1 and 1:1). The hydrogen fluoride can be fed either in thepure state or diluted with an inert gas (e.g., nitrogen, helium orargon).

CF₃CH═CFCF₃ can be prepared according to R. D. Chambers and A. J. P.Palmer, Tetrahedron, 25, 4217-24 (1969).1,3,3,4,4-pentafluorocyclobutene can be prepared according to R.Sullivan et al., J. Org. Chem., 29, 3664-68 (1964).1,3,3,4,4,5,5-heptafluorocyclopentene can be prepared according to R. E.Banks et al., J. Organomet. Chem., 29, 427-31 (1971).1,3,3,4,4,5,5,6,6-nonafluorocyclohexane can be prepared according to V.V. Bardin et al., J. Fluor. Chem., 49, 385-400 (1990).

Other olefinic starting materials for this process (e.g., the 5-8 carbonatom monohydrogen-containing olefinic materials of this inventionselected from the group consisting of CF₃CH═CFCF₂CF₃, CF₃CF═CHCF₂CF₃,CF₃CH═CF(CF₂)₂CF₃, CF₃CF₂CH═CFCF₂CF₃, CF₃(CF₂)₂CH═CFCF₃,CF₃CH═CF(CF₂)₃CF₃, CF₃CF₂CH═CF(CF₂)₂CF₃, CF₃(CF₂)₂CH═CFCF₂CF₃,CF₃(CF₂)₃CH═CFCF₃, CF₃CH═CF(CF₂)₄CF₃, CF₃CF₂CH═CF(CF₂)₃CF₃,CF₃(CF₂)₂CH═CF(CF₂)₂CF₃, CF₃(CF₂)₃CH═CFCF₂CF₃, and CF₃(CF₂)₄CH═CFCF₃)may be prepared by hydrogenating a corresponding perfluoroolefin andthen dehydrofluorinating the resulting dihydro-compound (i.e.,R⁷CF═CFR⁸+H₂→R⁷CHFCHFR⁸→R⁷CH═CFR⁸+R⁷CF═CHR⁸+HF, wherein R⁷ and R⁸ are asdefined above).

The olefins of the formula R⁷CF═CFR⁸ may be prepared as disclosed inabove referenced U.S. patent application Ser. No. 07/595,839. Accordingto the teaching therein, CF₃CF═CFCF₂CF₃ may be prepared by reactingperfluoropropene-2 with tetrafluoroethylene (TFE) by the proceduredescribed in Example C below. Perfluoropentene-2 may be converted to2H,3H-perfluoropentane by reaction of the olefin with hydrogen over aPd/alumina catalyst as described in Example 8 of above referenced U.S.patent application Ser. No. 07/595,840. 2H,3H-Perfluoropentane may beconverted to a mixture of 2H-perfluoropentene-2 and3H-perfluoropentene-2 by reaction over a carbon catalyst as described inExample 11 below.

Six-carbon monohydroperfluoroolefinic starting materials may be preparedby the following sequence of reactions. Six-carbon perfluoroolefinicstarting materials may be prepared by the reaction, substantially,according to the procedure of Example A in U.S. patent application Ser.No. 07/595,840, of 1,1,1,4,4,4-hexafluoro-2,3-dichloro-2-butene with TFEto yield an intermediate product comprisingperfluoro-2,3-dichloro-2-hexene. This product then can be converted to amixture of perfluoro-2-hexene and perfluoro-3-hexene by reaction withpotassium fluoride in refluxing N-methylpyrrolidone. Perfluoro-2-hexeneand perfluoro-3-hexene can be converted to CF₃CHFCHFCF₂CF₂CF₃ andCF₃CF₂CHFCHFCF₂CF₃ respectively by reaction of the olefin with hydrogenover a Pd/alumina catalyst as described in Example 8 of U.S. patentapplication Ser. No. 07/595,840. 2H,3H-Perfluorohexane and3H,4H-perfluorohexane can be converted to a mixture ofCF₃CH═CF(CF₂)₂CF₃, CF₃CF₂CH═CFCF₂CF₃, and CF₃(CF₂)₂CH═CFCF₃ by reactionover a carbon catalyst in a manner analogous to Example 11 below.

Seven-carbon monohydroperfluoroolefinic starting materials may beprepared by the following sequence of reactions. Seven-carbonperfluoroolefinic starting materials may be prepared by the reaction,substantially according to the procedure of Example 3 in U.S. patentapplication Ser. No. 07/595,839, of perfluoropropene-2 with two moles oftetrafluoroethylene to yield a product comprising perfluorohepteneisomers. Perfluoro-2-heptene and perfluoro-3-heptene can be converted toCF₃CHFCHF(CF₂)₃CF₃ and CF₃CF₂CHFCHF(CF₂)₂CF₃ respectively by reaction ofthe olefin with hydrogen over a Pd/alumina catalyst as described inExample 8 of U.S. patent application Ser. No. 07/595,840.2H,3H-Perfluoroheptane and 3H,4H-perfluoroheptane can be converted to amixture of CF₃CH═CF(CF₂)₃CF₃, CF₃CF₂CH═CF(CF₂)₂CF₃,CF₃(CF₂)₂CH═CFCF₂CF₃, and CF₃(CF₂)₃CH═CFCF₃ by reaction over a carboncatalyst in a manner analogous to Example 11 below.

Eight-carbon monohydroperfluoroolefinic starting materials may beprepared by the following sequence of reactions. Eight-carbonperfluoroolefinic starting materials may be prepared by the reaction,substantially according to the procedure of Example A in U.S. patentapplication Ser. No. 07/595,839, of1,1,1,4,4,5,5,6,6,6-decafluoro-2,3-dichloro-2-hexene with TFE to yieldan intermediate product comprising perfluoro-4,5-dichloro-4-octene. Thisproduct then may be converted to a mixture of perfluoro-2-octene,perfluoro-3-octene, and perfluoro-4-octene by reaction with potassiumfluoride in refluxing N-methylpyrrolidone. Perfluoro-2-octene,perfluoro-3-octene, and perfluoro-4-octene can be converted toCF₃CHFCHF(CF₂)₄CF₃, CF₃CF₂CHFCHF(CF₂)₃CF₃ and CF₃(CF₂)₂CHFCHF(CF₂)₂CF₃respectively by reaction of the olefin with hydrogen over a Pd/aluminacatalyst as described in Example 8 of U.S. patent application Ser. No.07/595,840. 2H,3H-Perfluoro-octane, 3H,4H-perfluoro-octane and4H,5H-perfluoro-octane can be converted to a mixture ofCF₃CH═CF(CF₂)₄CF₃, CF₃CF₂CH═CF(CF₂)₃CF₃, CF₃(CF₂)₂CH═CF(CF₂)₂CF₃,CF₃(CF₂)₃CH═CFCF₂CF₃ and CF₃(CF₂)₄CH═CFCF₃ by reaction over a carboncatalyst in a manner analogous to Example 11 below.

The gem-dihydropolyfluoroalkanes of this invention are useful assolvents (especially those compounds having boiling points of 100° C. orless) or as refrigerants. They are replacements for currentlyenvironmentally suspect chlorofluorocarbons such astrichlorotrifluoroethane. They have zero ozone depletion potential. Theyare non-flammable. These polyfluoroalkanes may be used by themselves orin combination with other miscible solvents as cleaning agents ordefluxing agents for solid surfaces, for example, printed wire boards.The compounds having boiling points above 75° C. are useful as vapordegreasers. The compounds of this invention may also be used as dryingagents.

Gem-dihydropolyfluoroalkanes of the formula R⁷CH₂CF₂R⁸ (wherein R⁷ andR⁸ are as described above) are miscible with various solventsconventionally used in cleaning operations. Compositions suitable foruse in cleaning operations can be prepared which comprise a mixture ofgem-dihydropolyfluoroalkanes of the formula R⁷CH₂CF₂R⁸ with one or morecompounds selected from the group consisting of alcohols, ethers,esters, ketones, nitromethane, acetonitrile, and halogenatedhydrocarbons. Of particular note are cleaning compositions whichcomprise a mixture of gem-dihydropolyfluoroalkanes of the formulaR¹CH₂CF₂R² (wherein R¹ and R² are as described above) with one or morealcohols, ethers, esters, ketones, nitromethane, acetonitrile and/orhalogenated hydrocarbons. The preferred alcohols and halogenatedhydrocarbons contain from 1 to 4 carbon atoms; the preferred etherscontain from 2 to 6 carbon atoms; and the preferred esters and ketonescontain from 3 to 6 carbon atoms. Examples of suitable alcohols includemethanol, ethanol and isopropanol. Examples of suitable ethers includetetrahydrofuran and diethyl ether. Examples of suitable ketones includeacetone and methylethylketone. Examples of suitable halogenatedhydrocarbons include methylene chloride (i.e., dichloromethane),1,1,2-trichloro-1,2,2-trifluoroethane, trichloroethene,1,1-dichloroethane, and cis- and trans-1,2-dichloroethylene. Preferably,such compositions contain at least about 5 percent by weight total ofthe gem-dihydropolyfluoro-alkanes of the formula R⁷CH₂CF₂R⁸ and/or theformula R¹CH₂CF₂R²; and can contain up to 99 percent by weight, or evenmore thereof. Preferred compositions include mixtures of one or more ofCF₃CH₂CF₂CF₂CF₃, CF₃CF₂CH₂CF₂CF₃, CF₃CH₂CF₂CF₂CF₂CH₃, andCF₃CF₂CH₂CF₂CF₂CF₃ with one or more of said alcohols, ethers, esters,ketones, nitromethane, acetonitrile and halogenated hydrocarbons. Mostpreferred with respect to ozone depletion potential are compositions inwhich no component contains chlorine.

The mixtures of this invention are useful in a wide variety of processesfor cleaning solid surfaces which comprise treating said surfacetherewith. Applications include removal of flux and flux residues fromprinted circuit boards contaminated therewith.

Compositions which comprise an admixture of effective amounts of one ormore gem-dihydropolyfluoroalkanes of the formula R⁷CH₂CF₂R⁸ and/or theformula R¹CH₂CF₂R² with one or more solvents selected from the groupconsisting of alcohols, ethers, esters, ketones, nitromethane,acetonitrile and halogenated hydrocarbons to form an azeotrope orazeotrope-like mixture are considered especially useful. Compositionswhich are mixtures of CF₃CH₂CF₂CF₂CF₃ and/or CF₃CF₂CH₂CF₂CF₃ withalcohol selected from the group consisting of methanol, ethanol andisopropanol are preferred.

By azeotrope or azeotrope-like is meant constant boiling liquidadmixtures of two or more substances which admixtures behave like asingle substance in that the vapor produced by partial evaporation ordistillation has the same composition as the liquid, i.e., theadmixtures distill without a substantial change in composition. Constantboiling compositions characterized as azeotropes or azeotrope-likeexhibit either a maximum or minimum boiling point as compared with thatof nonazeotropic mixtures of the same substances.

By effective amounts is meant the amounts of each component of theadmixture of the instant invention, which, when combined, results in theformation of the azeotrope or azeotrope-like admixture of the instantinvention.

It is possible to fingerprint, in effect, a constant boiling admixture,which may appear under varying guises depending on the conditionschosen, by any of several criteria.

The composition may be defined as an azeotrope of its components, saycomponent A and component B, since the very term “azeotrope” is at onceboth definitive and limitive, requiring that effective amounts of A andB form this unique composition of matter which is a constant boilingadmixture. It is well known by those who are skilled in the art that atdiffering pressures, the composition of a given azeotrope will vary, atleast to some degree, and changes in distillation pressures also change,at least to some degree, the distillation temperatures. Thus, anazeotrope of A and B represents a unique type of relationship but with avariable composition depending on temperature and/or pressure.Therefore, compositional ranges, rather than fixed compositions, areoften used to define azeotropes.

Or, the composition can be defined as a particular weight relationshipor mole percent relationship of A and B, while recognizing that suchspecific values point out only one particular such relationship and thatin actuality a series of such relationships represented by A and Bactually exist for a given azeotrope, varied by influence ofdistillative conditions of temperature and pressure.

Or, recognizing that the azeotrope A and B does represent just such aseries of relationships, the azeotropic series represented by A and Bcan be characterized by defining the composition as an azeotropecharacterized by a boiling point at a given pressure, thus givingidentifying characteristics without unduly limiting the scope of theinvention by a specific numerical composition, which is limited by andis only as accurate as the analytical equipment available.

Azeotrope or azeotrope-like compositions are provided in accordance withthis invention which comprise admixtures of effective amounts of agem-dihydropolyfluoroalkane (e.g., CF₃CH₂CF₂CF₂CF₃) with an alcoholselected from the group consisting of methanol, ethanol and isopropanolto form an azeotrope or azeotrope-like mixture.

In accordance with this invention, compositions which are two-componentmixtures of (i) from about 91 to 99 weight percent total of at least oneof CF₃CH₂CF₂CF₂CF₃ and CF₃CF₂CH₂CF₂CF₃, and (ii) from about 1 to 9weight percent methanol are characterized as azeotropes orazeotrope-like in that mixtures within this range exhibit asubstantially constant boiling point. Being substantially constantboiling, the mixtures do not tend to fractionate to any great extentupon evaporation. After evaporation, only a small difference existsbetween the composition of the vapor and the composition of the initialliquid phase. This difference is so small that the compositions of thevapor and liquid phases are considered substantially identical.Accordingly, any mixture within this range exhibit properties which arecharacteristic of a true binary azeotrope. The binary compositionconsisting essentially of about 95 weight percent CF₃CH₂CF₂CF₂CF₃ andabout 5 weight percent methanol has been established, within theaccuracy of the fractional distillation method, as a true binaryazeotrope, boiling at about 40° C. at substantially atmospheric pressureand is a preferred azeotrope of this invention.

Also, in accordance with this invention, compositions which aretwo-component mixtures of (i) from about 93 to 99 weight percent totalof at least one of CF₃CH₂CF₂CF₂CF₃ and CF₃CF₂CH₂CF₂CF₃, and (ii) fromabout 1 to 7 weight percent ethanol are characterized as an azeotrope orazeotrope-like in that mixtures within this range exhibit asubstantially constant boiling point. Being substantially constantboiling, the mixtures do not tend to fractionate to any great extendupon evaporation. After evaporation, only a small difference existsbetween the composition of the vapor and the composition of the initialliquid phase. This difference is so small that the compositions of thevapor and liquid phases are considered substantially identical.Accordingly, any mixture within this range exhibits properties which arecharacteristic of a true binary azeotrope. The binary compositionconsisting essentially of about 97 weight percent CF₃CH₂CF₂CF₂CF₃ andabout 3 weight percent ethanol has been established, within the accuracyof the fractional distillation method, as a true binary azeotrope,boiling at about 45° C. at substantially atmospheric pressure and is apreferred azeotrope of this invention.

Also, in accordance with this invention, compositions which aretwo-component mixtures of (i) from about 93 to 99 weight percent totalof at least one of CF₃CH₂CF₂CF₂CF₃and CF₃CF₂CH₂CF₂CF₃, and (ii) fromabout 1 to 7 weight percent isopropanol are characterized as anazeotrope or azeotrope-like in that mixtures within this range exhibit asubstantially constant boiling point. Being substantially constantboiling, the mixtures do not tend to fractionate to any great extentupon evaporation. After evaporation, only a small difference existsbetween the composition of the initial liquid phase. This difference isso small that the compositions of the vapor and liquid phases areconsidered substantially identical. Accordingly, any mixture within thisrange exhibits properties which are characteristic of a true binaryazeotrope. The binary composition consisting essentially of about 97weight percent CF₃CH₂CF₂CF₂CF₃ and about 3 weight percent isopropanolhas been established, within the accuracy of the fractional distillationmethod, as a true binary azeotrope, boiling at about 46 ° C. atsubstantially atmospheric pressure, and is a preferred azeotrope of thisinvention.

The compositions of the invention may be used in conventional apparatus,employing conventional operating techniques, The solvent(s) may be usedwithout heat if desired, but the cleaning action of the solvent may beassisted by conventional means (e.g., heating, agitation, etc.). In someapplications (e.g., removing certain tenacious fluxes from solderedcomponents) it may be advantageous to use ultrasonic irradiation incombination with the solvent(s).

Compositions provided in accordance with this invention can be used incleaning processes such as us described in U.S. Pat. No. 3,881,949 andU.S. Pat. No. 4,715,900, both of which are incorporated herein byreference.

The mixtures of the instant invention can be prepared by any convenientmethod including mixing or combining the desired amounts of thecomponents. A preferred method is to weigh the desired amounts of eachcomponent and thereafter combine them in an appropriate container.

Practice of the invention will become further apparent from thefollowing non-limiting examples.

EXAMPLES Example A CF₃CF═CFCF₂CF₃→CF₃CHFCHFCF₂CF₃ Palladium/Alumina

A 6″×½″ O.D. Hastelloy™ nickel alloy tube reactor was charged with 0.5%Pd/alumina (10.0 g, 5×8 mesh spheres). This catalyst was reduced withhydrogen prior to use. Vaporized perfluoropentene-2 (2 mL/hr) andhydrogen (20 cc/min) were co-fed to the reactor. The reaction productswere analyzed by on-line GC and on-line MS and the products werecollected in a −80° C. trap. At temperatures of 100-200° C., conversionswere 96-99% and ≧95% yields of perfluoro-2H,3H-pentane were obtained.The major by-products were about 1% of the trihydroperfluoropentanes.Pure dihydro-product, bp 50-55° C. was obtained by a simplefractionation and was shown by GC and NMR analyses to have a ratio ofdiastereomers of about 9:1.

Example B CF₃CF═CFCF₂CF₃→CF₃CHFCHFCF₂CF₃ Hydrogen/Iodine

A metal rocker tube charged with iodine (97.4 g, 0.384 mol) andperfluoropentene-2 (191.8 g, 0.767 mol) was cooled, evacuated, pressuredwith hydrogen (100 psi), and heated to 300° C. The hydrogen pressure wasraised to and maintained at 1000 psi and 300° C. for one day. The rockertube was cooled to 5° C. gases vented, and the cold product (157.2 g,99% pure by GC) was washed with cold aqueous Na₂S₂O₃, dried over Na₂SO₄,to yield decafluoro-2H,3H-pentane, bp 43-52° C., as two diastereomers ina 49:51 ratio.

Example C Preparation of CF₃CF═CFCF₂CF₃

A 400 mL metal tube charged at −20° C. with AlF_(2.8)Cl_(0.2) (8.0 g),prepared from AlCl₃ and CCl₃F, hexafluoropropene (75.0 g, 0.50 mol), andtetrafluoroethylene (50 g, 0.50 mol) was shaken for 30 min. During thistime the temperature rose quickly to 20° C. and the pressure dropped to8 psi. Distillation of the product afforded perfluoropentene-2 (88.0 g,70% yield), bp 23-26° C., identified by IR, NMR and GC/MS. NMR showedthe product to contain 89% of the trans-isomer and 11% of thecis-isomer.

Example D Preparation of CF₃CH═CFCF₂CF₃

A 400 mL metal tube charged at −20° C. with AlF_(2.8)Cl_(0.2) (6.0 g),prepared from AlCl₃ and CCl₃F, 2H-pentafluoropropene (66.0 g, 0.50 mol),and tetrafluoroethylene (50 g, 0.50 mol) was shaken for 3.5 hr. Duringthis time the temperature rose quickly to 25° C. and the pressuredropped to 0 psi from an initial pressure of 153 psi. Distillation ofthe product afforded 80% 2H-perfluoropentene-2 identified by IR, NMR andGC/MS.

Example 1 Addition to HF to Nonafluoro-2H-pentene-2 to FormDecafluoro-2H,2H-pentene (HFC-43-10mf) CF₃CH═CFCF₂CF₃+HF→CF₃CH₂CF₂CF₂CF₃

A 200mL Hastelloy® nickel alloy tube charged with PCB carbon (25 g,previously dried under vacuum at 300-350° C.), nonafluoro-2H-pentene-2(23.2 g, 0.10 mol), and HF (10 g, 0.5 mol) was heated at 300° C. for 4hr under autogenous pressure. The tube was cooled, and the recovered dryblack solid was stirred with a solution of calcium chloride (20 g) inwater (100 mL), then distilled to give a two-phase distillate. The lowerlayer (15 g), was indicated by GC/MS to consist of 54.6% of startingolefin and 45.1% of decafluoro-2H,2H-pentane, with minor amounts of twoimpurities.

The distilled dihydro-product ca. 98% pure, bp 46-47° C. wascharacterized by ¹H and ¹⁹F NMR and the structure was confirmed asdecafluoro-2H,2H-pentane, IR (neat): 3029 and 2987 (sat'd CH), 1300-1150cm⁻¹ (CF).

Example 2 Addition of HF to Nonafluoro-2H-pentene-2 to FormDecafluoro-2H,2H-pentane (HFC-43-10mf) CF₃CH═CFCF₂CF₃+HF→CF₃CH₂CF₂CF₂CF₃

A 200-mL Hastelloy® nickel alloy tube charged with PCB carbon (25 g,previously dried under vacuum at 300-350° C.), nonafluoro-2H-pentene-2(23.3 g, 0.10 mol), and HF (10 g, 0.5 mol) was heated at 300° C. for 12hr under autogenous pressure. The tube was cooled, and the recovered dryblack solid was stirred with a solution of calcium chloride (20.8 g) inwater (100 mL), then distilled to give a two-phase distillate. Analysisof the crude volatile product showed it to contain 13% of startingolefin and 87% of decafluoro-2H,2H-pentane.

Example 3 Addition of HF to Nonafluoro-2H-pentene-2 to FormDecafluoro-2H,2H-pentane (HFC-43-10mf) CF₃CH═CFCF₂CF₃+HF→CF₃CH₂CF₂CF₂CF₃

A 1.4 L Hastelloy® nickel alloy tube charged with PCB carbon (175 g,previously dried in a stream of nitrogen at 150° C.),nonafluoro-2H-pentene-2 (170 g, 0.73 mol), and HF (70 g, 3.5 mol) washeated at 300° C. for 16 hr under autogenous pressure. The tube wascooled, and the recovered dry black solid was stirred with a solution ofcalcium chloride (210 g) in water (800 mL), then distilled to give atwo-phase distillate. The lower layer (100.5 g) gave 25% isolated yield(46.9 g) of decafluoro-2H,2H-pentane, bp 47° C.

Example 4 Addition of HF to Heptafluoro-1H-cyclopentene to FormOctafluoro-1H,1H-cyclopentane

Heptafluoro-1H-cyclopentene was prepared as described in U.S. Pat. No.3,449,304 (col. 1, line 47 through col. 2, line 39). A mixture of driedPCB carbon (25 g) heptafluoro-1H-cyclopentene (24 g, 0.12 mol) and HF(10 g, 0.5 mol) was heated in a 200-mL Hastelloy® nickel alloy tube at300° C. for 12 hr. The product was contact with aq. CaCl₂ and distilledin the usual way to give 5.0 g of liquid, indicated by GC/MS to contain59.1% of starting cycloolefin and 40.3% of product C₅H₂F₈. NMR showedthe 40.3% component to be octafluoro-1H,1H-cyclopentane.

Example 5 Rearrangement of Decafluoro-2H,3H-pentane toDecafluoro-2H,2H-pentane and Decafluoro-3H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH₂CF₂CF₂CF₃+CF₃CF₂CH₂CF₂CF₃

A mixture of decafluoro-2H,3H-pentane (25.4 g, 0.10 mol), prepared asdescribed above in Example B, dried PCB carbon (25 g), and HF (10 g, 0.5mol) was heated in a 200mL Hastelloy® nickel alloy tube at 300° C. for12 hr.

Work-up of the reaction mixture in the usual way by contacting with aq.CaCl₂ and distillation afforded 12.3 of liquid. Analysis by GC/MS and ¹Hand ¹⁹F NMR showed it to contain 25% of decafluoro-2H,2H-pentane, 18.5%of decafluoro-3H,3H-pentane, 15% of nonafluoro-2H-pentene-2, and 4% ofnonafluoro-3H-pentene-2, along with 36.5% of recovered 2H,3H startingmaterial.

Example 6 Rearrangement of Decafluoro-2H,3H-pentane toDecafluoro-2H,2H-pentane and Decafluoro-3H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH₂CF₂CF₂CF₃+CF₃CF₂CH₂CF₂CF₃

A mixture of decafluoro-2H,3H-pentane (25.2 g, 0.10 mol), prepared asdescribed above in Example B, dried 2% CrCl₃ on PCB carbon (20 g), andHF (10 g, 0.5 mol) was heated in a 200 mL Hastelloy® nickel alloy tubeat 300° C. for 12 hr.

Work-up of the reaction mixture in the usual way by contacting with aq.CaCl₂ and distillation afforded 13.0 g of liquid. Analysis by GC/MS and¹H and ¹⁹F NMR showed it to contain 4.1% of decafluoro-2H,2H-pentane,4.1% of decafluoro-3H,3H-pentane, 8.2% of nonafluoro-2H-pentene-2, and3.1% of nonafluoro-3H-pentene-2, along with 80.6% of recovered 2H,3Hstarting material.

Example 7 Rearrangement of Decafluoro-2H,3H-pentane toDecafluoro-2H,2H-pentane and Decafluoro-3H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH₂CF₂CF₂CF₃+CF₃CF₂CH₂CF₂CF₃

A mixture of decafluoro-2H,3H-pentane (25.2 g, 0.10 mol), prepared asdescribed above in Example B, dried 2% Darco™ activated carbon (23 g,4×12 mesh), and HF (10 g, 0.5 mol) was heated in a 200 mL Hastelloy®nickel alloy tube at 300° C. for 12 hr.

Work-up of the reaction mixture in the usual way by contacting with aq.CaCl₂ and distillation afforded 14.0 of liquid. Analysis by GC/MS and ¹Hand ¹⁹F NMR showed it to contain 3.8% of decafluoro-2H,2H-pentane, 4.1%of decafluoro-3H,3H-pentane, 14.0% of nonafluoro-2H-pentene-2, and 5.1%of nonafluoro-3H-pentene-2, 3.2% nonafluoro-2H,2H,3H-pentane, 1.3%nonafluoro-2H,3H,3H-pentane, along with 67.3% of recovered 2H,3Hstarting material.

Example 8 Rearrangement of Decafluoro-2H,3H-pentane toDecafluoro-2H,2H-pentane and Decafluoro-3H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH₂CF₂CF₂CF₃+CF₃CF₂CH₂CF₂CF₃

A mixture of decafluoro-2H,3H-pentane (25 g, 0.10 mol), prepared asdescribed above in Example B, dried PCB carbon of the type listed as NAWin Table 1 below (25 g, 12×30 mesh), and HF (10 g, 0.5 mol) was heatedin a 200 mL Hastelloy™ nickel alloy tube at 300° C. for 12 hr.

Work-up of the reaction mixture in the usual way by contacting with aq.CaCl₂ and distillation afforded 11.1 g of liquid. Analysis by GC/MS and¹H and ¹⁹F NMR showed it to contain 5.6% of decafluoro-2H,2H-pentane,5.6% of decafluoro-3H,3H-pentane, 8.8% of nonafluoro-2H-pentene-2, and2.5% of nonafluoro-3H-pentene-2, along with 77.5% of recovered 2H,3Hstarting material.

Example 9 Rearrangement of Decafluoro-2H,3H-pentane toDecafluoro-2H,2H-pentane and Decafluoro-3H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH₂CF₂CF₂CF₃+CF₃CF₂CH₂CF₂CF₃

A mixture of decafluoro-2H,3H-pentane (25 g, 0.10 mol), prepared asdescribed above in Example B, dried HCl-washed (traces only of K⁺ left)PCB carbon (10.4 g, 12×30 mesh), and HF (10 g, 0.5 mol) was heated in a200 mL Hastelloy® nickel alloy tube at 300° C. for 12 hr.

Work-up of the reaction mixture in the usual way by contacting with aq.CaCl₂ and distillation afforded 11.0 g of liquid. Analysis by GC/MS and¹H and ¹⁹F NMR showed it to contain 2.1% of decafluoro-2H,2H-pentane,2.1% of decafluoro-3H,3H-pentane, 5.2% of nonafluoro-2H-pentene-2, and2.1% of nonafluoro-3H-pentene-2, along with 88.7% of recovered 2H,3Hstarting material.

Comparative Example Rearrangement of Decafluoro-2H,3H-pentane toDecafluoro-2H,2H-pentane and Decafluoro-3H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH₂CF₂CF₂CF₃+CF₃CF₂CH₂CF₂CF₃

A mixture of decafluoro-2H,3H-pentane (25 g, 0.10 mol as a mixture oftwo disastereomers in 96:4 ratio), prepared by the hydrogenation ofperfluoropentene-2 over a 5% Pd on carbon catalyst; and HF (10 g, 0.5mol) was heated in a 200 mL Hastelloy® nickel alloy tube at 300° C. for12 hr.

Work-up of the reaction mixture in the usual way by contacting with aq.CaCl₂ and distillation afforded 9.9 g of liquid. Analysis by GC/MS and¹H and ¹⁹F NMR showed it to contain only recovered 2H,3H startingmaterial.

Example 10 Rearrangement of Octafluoro-2H,3H-butane toOctafluoro-2H,2H-butane CF₃CHFCHFCF₃→CF₃CH₂CF₂CF₃

Reaction of octafluoro-2H,3H-butane (20 g, 0.099 mol) with of PCB carbon(25 g) and HF (10 g, 0.50 mol) for 12 hr at 300° C. gave, aftercontacting with aq. CaCl₂, 8.3 g of volatiles. Analysis by GC/MS and NMRshowed 3.4% of octafluoro-2H,2H-butane and 2.1% ofheptafluoro-2H-butene-2to be present as products.

General Procedure for Examples 11-15

The reactor (0.5 inch ID×12 inch Inconel® nickel alloy pipe) was chargedwith a catalyst and placed in a sand bath. The bath was gradually heatedto 400° C. while nitrogen gas at a flow rate of 50 cc/min. was passedthrough the reactor to remove traces of water. After the water wasremoved, the temperature of the bath was adjusted to the indicated valueand HF and 1,1,1,2,3,4,4,5,5,5-decafluoropentane (HFC-43-10mee) were fedto the reactor. The HFC-43-10mee was a 99% pure mixture of diastereomerscontaining small amounts of the following impurities; CF₃CHFCHF₂,CF₃CF═CFC₂F₅, and unknowns.

The reactor effluent was sampled on-line with a Hewlett Packard HP 5890gas chromatography using a 20 ft. long, ⅛″ diameter, column containingKrytox® perfluorinated polyether on an inert support and a helium flowof 35 cc/min. Gas chromatographic conditions were 70° C. for 3 min.followed by temperature programming to 180° C. at a rate of 6° C./min.Product analyses are reported as relative area %.

Example E Preparation of HCl-Washed Carbon

A commercially available carbon (500 g, 6×16 mesh granules) was soakedfor 120 hr with gentle stirring in 1M HCl. The carbon granules werecollected on a fritted glass funnel and washed with deionized wateruntil the washings were chloride free. Finally the carbon granules weredried at 120° C. for 60 hr followed by calcination at 300° C. in air toobtain 468.8 g of dried, calcined granules. The ash content and theelements present in the ash are shown in Table 1.

Example F Preparation of HCl/HF-Washed Carbon

HCl-washed carbon (225 g, 6×16 mesh granules) prepared as describedabove was soaked in for 48 hr at room temperature with occasionalstirring in 1M HF (3 L) in an HF-resistant container. The carbongranules were then placed in a 4 L HF-resistant container on a steambath and washed with deionized water (3 L portions, at about 50° C.)until the washings had a pH greater than 4.0. Finally the carbongranules were dried at 150° C. for 60 hr in air followed by calcinationat 300° C. in air for 3 hr to obtain 216.6 g of dried calcined granules.The ash content and the elements present in the ash are shown in Table1.

Example G Preparation of CrCl₃ On HCl-Washed Carbon

CrCl₃.6H₂O (4.04 g) was dissolved in deionized water (56 mL) and theentire solution poured over 40 g of HCl-washed carbon granules (6×16mesh). The resulting mixture was allowed to stand at room temperaturefor 1 hr and then placed in a convection oven at 120° C. for 16 to 24 hrto remove the water. It was then pretreated by heating in an atmosphereof nitrogen gas at 450° C. followed by heating in HF at 450° C. prior toits use as a catalyst.

TABLE 1 Elemental Analysis of Carbon Granules C1W^((a)) C1FW^((b))NAW^((c)) (ppm) (ppm) (ppm) P 330 S 380 Si 760 74 900 Cu 18 3 21 Mn 1 <115 Fe 65 25 205 Ba <1 12 Ca 17 650 Zn <3 <1 <5 Mg 21 K 28 9500 Al <240290 Na 250 730 Ti <30 12 10 Ash 0.18% 0.01% 2.18% ^((a))C1W = HCl-washedcarbon ^((b))C1FW = HCl/HF-washed carbon ^((c))NAW = non-acid washedcarbon

Example 11 Dehydrofluorination of Decafluoro-2H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH═CFCF₂CF₃+CF₃CF₂CH═CFCF₃

The General Procedure described above was followed. The catalyst was acommercial PCB carbon (15.6 g, 30 mL, 12×30 mesh). HF and HFC-43-10meein a molar ratio of 2:1 and with a contact time of 60 sec. atatmospheric pressure were fed to the reactor. The results of experimentsat different temperatures are shown in Table 2.

TABLE 2 43-10mee F1429 F1438 43-10mcf 43-10mf Time Temp. (a) (b) (c) (d)(e) hr. ° C. % Conv % Sel. % Sel. % Sel. % Sel. 1 400 100 93.0 2.4 0.50.5 2 400 100 94.1 0.5 0.5 0.5 3 400 100 94.1 0.3 0.5 0.5 4 400 100 93.70.2 0.5 0.6 5 350 100 94.1 <0.1 1.4 1.8 6 325 100 91.3 0.2 2.2 3.9 7 30098.8 86.0 0.1 3.5 8.0 8 275 82.7 80.2 <0.1 6.0 11.7 9 250 43.8 77.3 0.29.2 10.4 10  225 9.6 80.8 0.2 6.3 5.0 (a) 43-10mee is a 99% pure mixtureof CF₃CHFCHFCF₂CF₃ diastereomers. (b) F1429 is a mixture of cis andtrans isomers of CF₃CH═CFCF₂CF₃ and CF₃CF₂CH═CFCF₃ and trace amounts ofother olefins. (c) F1438 is an olefin of the formula C₅H₂F₈. (d)43-10mcf is CF₃CF₂CH₂CF₂CF₃. (e) 43-10mf is CF₃CH₂CF₂CF₂CF₃.

Example 12 Dehydrofluorination of Decafluoro-2H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CH═CFCF₂CF₃+CF₃CF₂CH═CFCF₃

The General Procedure described above was followed. The catalyst was acommercial carbon that had been washed with hydrochloric andhydrofluoric acid (13.4 g, 30 mL, 6×16 mesh). HF and HFC-43-10mee in amolar ratio of 2:1, 4:1, or 6:1 and with a contact time of 60 sec. werefed to the reactor. The results of experiments at different temperaturesare shown in Table 3.

TABLE 3 43-10mee F1429 43-10mcf 43-10mf Time Temp. molar (b) (c) (d) (e)hr. ° C. ratio^((a)) % Conv % Sel. % Sel. % Sel.  1 200 2:1 0.9 99.9 — — 3 225 4:1 8.3 94.5 4.2 1.3  4 250 4:1 31.2 90.5 6.7 2.8  7 250 2:1 12.594.7 3.1 2.2 11 275 2:1 36.4 93.1 3.9 3.0 25 275 4:1 54.0 89.2 5.8 5.031 275 6:1 57.0 88.1 6.2 5.6 36 300 2:1 73.0 92.6 3.4 4.0 48 300 4:192.4 89.0 4.0 7.1 56 300 6:1 93.2 88.3 4.1 7.6 59 325 2:1 99.1 93.8 2.14.1 61 325 4:1 99.8 93.1 2.4 4.4 63 350 2:1 100 96.8 1.2 2.0 64 350 0:1100 97.7 0.9 1.3 ^((a))molar ratio of HF:43-10mee. (b) 43-10mee is a 99%pure mixture of CF₃CHFCHFCF₂CF_(3 diastereomers.) (c) F1429 is a mixtureof cis and trans isomers of CF₃CH═CFCF₂CF₃ and CF₃CF₂CH═CFCF₃ and traceamounts of other olefins. (d) 43-10mcf is CF₃CF₂CH₂CF₂CF₃. (e) 43-10mfis CF₃CH₂CF₂CF₂CF₃.

Example 13 Dehydrofluoroination of Decafluoro-2H,3H-pentaneCF₃CHFCHFCH₂CF₃→CF₃CH═CFCF₂CF₃+CF₃CF₂CH═CFCF₃

The General Procedure described above was followed. The catalyst was 6%CrCl₃/acid-washed carbon (14.7 g, 30 mL) prepared as described inExample C. HF and HFC-43-10mee in a molar ratio of 2:1 or 4:1, and witha contact time of 60 sec. were fed to the reactor. The results ofexperiments at different temperatures are shown in Table 4.

TABLE 4 43-10mee F1429 43-10mcf 43-10mf Time Temp. molar (b) (c) (d) (e)hr. ° C. ratio^((a)) % Conv % Sel. % Sel. % Sel. 1 200 2:1 0.9 99.9 — —3 225 2:1 5.8 94.4 3.7 1.9 4 225 4:1 5.3 97.2 1.9 0.9 5 250 4:1 19.993.2 4.4 2.4 6 275 4:1 40.2 91.7 4.5 3.8 7 300 4:1 73.1 91.8 3.2 4.5 8325 4:1 99.7 91.7 2.4 4.5 9 350 4:1 99.9 94.2 1.5 2.1 10  375 4:1 99.994.1 1.0 1.0 ^((a))molar ratio of HF:43-10mee. (b) 43-10mee is a 99%pure mixture of CF₃CHFCHFCF₂CF_(3 diastereomers.) (c) F1429 is a mixtureof cis and trans isomers of CF₃CH═CFCF₂CF₃ and CF₃CF₂CH═CFCF₃ and traceamounts of other olefins. (d) 43-10mcf is CF₃CF₂CH₂CF₂CF₃. (e) 43-10mfis CF₃CH₂CF₂CF₂CF₃.

Example 14 Dehydrofluoroination and Rearrangement ofDecafluoro-2H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CF₂CH₂CF₂CF₃+CF₃CH₂CF₂CF₂CF₃+CF₃CH═CFCF₂CF₃+CF₃CF₂CH═CFCF₃

The General Procedure described above was followed. The reactor was a ¾″OD×6″ length Inconel® nickel alloy pipe. The catalyst was a carbon thathad been washed with hydrochloric and hydrofluoric acid (13.2 g, 30 mL,6×16 mesh). HF and HFC-43-10mee in a molar ratio of 4:1 were fed to thereactor at 300° C. The results of experiments at different pressures,100 psi and 200 psi, are shown in Table 5. The conversion ofHFC-43-10mee was complete in both cases.

TABLE 5 Press. F1429^((a)) 43-10mcf^((b)) 43-10mf^((c)) psi % Sel. %Sel. % Sel. 100 43.9 16.6 32.7 200 34.4 20.8 40.6 ^((a))F1429 is amixture of cis and trans isomers of CF₃CH═CFCF₂CF₃ and CF₃CF₂CH═CFCF₃and trace amounts of other olefins. ^((b))43-10mcf is CF₃CF₂CH₂CF₂CF₃.^((c))43-10mf is CF₃CH₂CF₂CF₂CF₃.

Example 15 Dehydrofluoroination and Rearrangement ofDecafluoro-2H,3H-pentaneCF₃CHFCHFCF₂CF₃→CF₃CF₂CH₂CF₂CF₃+CF₃CH₂CF₂CF₂CF₃+CF₃CH═CFCF₂CF₃+CF₃CF₂CH═CFCF₃

The General Procedure described above was followed. The reactor was a ¾″OD×6″ length Inconel® nickel alloy pipe. The catalyst was a carbon thathad been washed with hydrochloric and hydrofluoric acid (13.2 g, 30 mL,6×16 mesh). HFC-43-10mee (3.6 mL/hr) was fed to the reactor at 300° C.and at 200 psi. The results are shown in Table 6. The conversion ofHFC-43-10mee was 100% complete.

TABLE 6 F1429 43-10mcf 43-10mf % Sel. % Sel. % Sel. 52.6 15.4 30.3

Example 16 HFC-43-10mf/Methanol

HFC-43-10mf (18.1 g) and methanol (1.0 g) were combined and the mixturewas distilled using a spinning band column. The boiling point andcomposition were monitored for azeotrope formation. A constant boilingazeotrope was formed which had a boiling point of about 40.4° C. Gaschromatographic analysis showed that the azeotrope consisted of 94.4%HFC-43-10mf and 5.1% methanol.

Example 17 HFC-43-10mf/Ethanol

HFC-43-10mf (17.5 g) and absolute ethanol (1.0 g) were combined and themixture was distilled using a spinning band column. The boiling pointand composition were monitored for azeotrope formation. A constantboiling azeotrope was formed which had a boiling point of about 44.6° C.Gas chromatographic analysis showed that the azeotrope consisted of96.7% HFC-43-10mf and 3.3% ethanol.

Example 18 HFC-43-10mf/Isopropanol

HFC-43-10mf (12.0 g) and isopropanol (1.0 g) were combined and themixture was distilled using a spinning band column. The boiling pointand composition were monitored for azeotrope formation. A constantboiling azeotrope was formed which had a boiling point of about 46.0° C.Gas chromatographic analysis showed that the azeotrope consisted of97.0% HFC-43-10mf and 3.0% isopropanol.

Example 19 Surface Cleaning with HFC-43-10mf/Methanol Azeotrope

A single-sided circuit board is coated with activated rosin flux, andsoldered by passing the board over a preheater to obtain a top sideboard temperature of approximately 200° F. and then through 500° F.molten solder. The soldered board is defluxed in an azeotropic mixtureof 94.9 weight percent HFC-43-10mf and 5.1 weight percent methanol bysuspending it, first for 3 min. in the boiling sump, then 1 min. in therinse sump and, thereafter, for 1 min. in the solvent vapor above theboiling sump. The board thus cleaned has no visible residue remaining onit.

Particular embodiments of the invention are included in the Examples.Other embodiments will become apparent to those skilled in the art froma consideration of the specification or practice of the inventiondisclosed herein. It is understood that modifications and variations maybe practiced without departing from the spirit and scope of the novelconcepts of this invention. It is further understood that the inventionis not confined to the particular formulations and examples hereinillustrated, but it embraces such modified forms thereof as come withinthe scope of the following claims.

What is claimed is:
 1. A compound having the formula R¹CH₂CF₂R² whereinR¹ is selected from the group consisting of —CF₂CF₃ and —CF₂CF₂CF₃ andR² is selected from the group consisting of —CF₃, —CF₂CF₃ and —CF₂CF₂CF₃or wherein R¹ and R² together are —(CF₂)₃—.
 2. The compound of claim 1which is CF₃CF₂CH₂CF₂CF₂CF₂CF₂CF₃.
 3. The compound of claim 1 which isCF₃CF₂CF₂CH₂CF₂CF₂CF₂CF₃.
 4. The compound of claim 1 which isCF₃CF₂CF₂CH₂CF₂CF₂CF₃.
 5. The compound of claim 1 which isCF₃CF₂CH₂CF₂CF₂CF₂CF₂.
 6. The compound of claim 1 which isCF₃CF₂CH₂CF₂CF₂CF₃.
 7. The compound of claim 1 which is CF₃CF₂CH₂CF₂CF₃.8. The compound of claim 1 which is